Telephone system installations in multi-occupant facilities, where each occupant of the facility has a different telephone number and a plurality of extensions, in the past have been arranged either: (a) as separate user systems set up by the occupants individually and separately connected to a public switched telephone network (PSTN) through a local telephone switch or router each dedicated to the individual user telephone system, or (b) as multi-exchange shared systems set up by, for example, the landlords of the facilities, with each individual user telephone exchange system in the overall shared system connected to a public switched is telephone network though a private branch exchange (PBX) used in common by the plurality of occupants of the facility, or (c) as separate user systems set up by the occupants individually and separately connected directly to a public switched telephone network.
Such prior art telephone installations in multi-occupant facilities suffer from one or more of the following shortcomings. One shortcoming is the expenses associated with the individual installation and maintenance of telephone systems installed and maintained by the users. Another is the high cost of the private branch exchange that is included in a shared multi-exchange system. A shortcoming common to both prior art arrangements is the large number of cable pairs that is required for conventional telephone voice transmissions. Yet another shortcoming of many such prior art multi-user telephone installations is that only voice transmission and reception are provided, so that another communications system, capable of transmitting and receiving data, is needed for those users that transmit and receive data. Still another shortcoming of many such prior art multi-user telephone installations is that they transmit and receive voice transmissions by conventional telephonic means at higher costs than voice transmissions by voice over Internet protocol (VOIP).